Vehicle power transfer unit (PTU) with planetary gear set

Abstract

One implementation of a vehicle power transfer unit (PTU) assembly—such as thatfor an automobile—includes an input shaft, a planetary gear set, an intermediate shaft, a ring gear, and an output gear. The planetary gear set includes a sun gear, multiple planet gears, and an annular gear. The sun gear is attached to a housing of the vehicle PTU and does not rotate in use. The planet gears are interconnected to the input shaft and are driven by the input shaft. The annular gear is in turn driven by the planet gears. The intermediate shaft is interconnected to and driven by the annular gear. The ring gear is interconnected to the intermediate shaft, and the output gear is driven by the ring gear.

What is claimed is: 
     
       1. A vehicle power transfer unit (PTU) assembly, comprising:
 an input shaft rotating about a first axis; 
 a planetary gear set driven by said input shaft, said planetary gear set including a sun gear, a plurality of planet gears, and an annular gear, said sun gear being fixed against rotation, said plurality of planet gears interconnected to said input shaft and driven by said input shaft and revolving around said sun gear, said annular gear driven by said plurality of planet gears; 
 an intermediate shaft rotating about the first axis and interconnected to said annular gear and driven by said annular gear; 
 a ring gear interconnected to said intermediate shaft and rotating with said intermediate shaft; and 
 an output gear rotating about a second axis arranged at an angle relative to the first axis, said output gear driven by said ring gear. 
 
     
     
       2. A vehicle power transfer unit (PTU) assembly as set forth in  claim 1 , wherein said input shaft and said planetary gear set are coaxial relative to each other about the first axis with said plurality of planet gears revolving around the first axis. 
     
     
       3. A vehicle power transfer unit (PTU) assembly as set forth in  claim 1 , wherein the interconnection between said input shaft and said plurality of planet gears is a direct interconnection without an intermediate component therebetween. 
     
     
       4. A vehicle power transfer unit (PTU) assembly as set forth in  claim 1 , wherein the interconnection between said annular gear and said intermediate shaft is a direct interconnection without an intermediate gear therebetween. 
     
     
       5. The assembly as set forth in  claim 4  wherein the input shaft includes a tubular main body and a flange that is formed from the same piece of material as the main body and extends radially outwardly from the main body, and wherein said plurality of planet gears are connected to the flange for rotation with the input shaft about the first axis. 
     
     
       6. A vehicle power transfer unit (PTU) assembly as set forth in  claim 1 , wherein said intermediate shaft is a sleeve shaft overlapping said input shaft at a radially outward location of said input shaft. 
     
     
       7. A vehicle power transfer unit (PTU) assembly as set forth in  claim 6 , wherein said ring gear rotates with said sleeve shaft about the first axis. 
     
     
       8. A vehicle power transfer unit (PTU) assembly as set forth in  claim 1 , wherein said ring gear directly drives said output gear via direct gear-to-gear driving. 
     
     
       9. A vehicle power transfer unit (PTU) assembly as set forth in  claim 8 , wherein said output gear is a pinion gear. 
     
     
       10. A vehicle power transfer unit (PTU) assembly as set forth in  claim 1 , wherein the second axis is arranged orthogonally relative to the first axis. 
     
     
       11. A vehicle power transfer unit (PTU) assembly as set forth in  claim 1 , wherein the vehicle PTU assembly is free of a clutch mechanism installed among said input shaft, said planetary gear set, said intermediate shaft, said ring gear, and said output gear. 
     
     
       12. The vehicle power transfer unit (PTU) assembly as set forth in  claim 1  wherein the annular gear has a unitary extension and the intermediate shaft is connected to the annular gear via the unitary extension so that the intermediate shaft and annular gear rotate together. 
     
     
       13. The vehicle power transfer unit (PTU) assembly as set forth in  claim 12  wherein the annular gear includes a sidewall and the unitary extension includes an axially extending flange projecting from the sidewall. 
     
     
       14. A vehicle power transfer unit (PTU) assembly, comprising:
 an input shaft; 
 a planetary gear set coaxial with said input shaft and including a sun gear, a plurality of planet gears, and an annular gear, said sun gear held against rotation and remaining stationary relative to said plurality of planet gears when the vehicle PTU is in use, said plurality of planet gears directly interconnected to said input shaft without an intermediate component therebetween and driven by said input shaft and revolving around said sun gear, said annular gear directly driven by said plurality of planet gears via gear-to-gear driving; 
 a sleeve shaft coaxial with said input shaft and directly interconnected to said annular gear without an intermediate gear therebetween, said sleeve shaft driven by said annular gear; 
 a ring gear coaxial with said input shaft and carried by said sleeve shaft; and 
 a pinion gear non-coaxial with said input shaft and directly driven by said ring gear via gear-to-gear driving. 
 
     
     
       15. The assembly as set forth in  claim 14 , wherein said input shaft and said planetary gear set are coaxial relative to each other about a first axis with said plurality of planet gears revolving around the first axis. 
     
     
       16. The assembly as set forth in  claim 14 , wherein said sleeve shaft radially overlaps at least part of said input shaft. 
     
     
       17. The assembly as set forth in  claim 16 , wherein said ring gear rotates with said sleeve shaft about a first axis. 
     
     
       18. The assembly as set forth in  claim 17 , wherein said pinion gear rotates about a second axis that is not parallel to the first axis. 
     
     
       19. The assembly as set forth in  claim 18 , wherein said second axis is orthogonal to the first axis. 
     
     
       20. The assembly as set forth in  claim 14  wherein the plurality of planet gears are directly coupled to the input shaft so that the planet gears co-rotate with the input shaft about the first axis, and wherein each planet gear also rotates relative to the input shaft about a separate axis of rotation that is offset from the first axis. 
     
     
       21. The assembly as set forth in  claim 20  wherein the input shaft includes a tubular main body and a flange that is formed from the same piece of material as the main body and extends radially outwardly from the main body, and wherein said plurality of planet gears are connected to the flange for rotation with the input shaft. 
     
     
       22. The assembly as set forth in  claim 14  wherein the annular gear has a unitary extension and the intermediate shaft is connected to the annular gear via the unitary extension so that the intermediate shaft and annular gear rotate together. 
     
     
       23. The assembly as set forth in  claim 22  wherein the annular gear includes a sidewall and the unitary extension includes an axially extending flange projecting from the sidewall.